US EPA

1519055 

Journal Article 

XANES evidence of arsenate removal from water with magnetic ferrite 

Tu, Y-J; You, C-F; Chang, C-K; Wang, S-L 

2013 

Yes 

Journal of Environmental Management
ISSN: 0301-4797
EISSN: 1095-8630 

Elsevier 

120 

Elsevier 

114-119 

English 

23507250 

10.1016/j.jenvman.2013.02.006 

WOS:000318000300015 

https://linkinghub.elsevier.com/retrieve/pii/S0301479713000856
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Arsenic (As) in groundwater and surface water is a worldwide problem possessing a serious threat to public health. In this study, a magnetic ferrite, was synthesized and investigated for its As(V) removal efficiency. The adsorption of As(V) by magnetic ferrite exhibited an L-shaped nonlinear isotherm, suggesting limiting binding sites on the adsorbent surface. The As K-edge X-Ray Absorption Near-Edge Structure (XANES) revealed that the adsorbed As(V) on ferrite was not reduced to more toxic As(III) by Fe(2+) in the ferrite structure. The maximum As adsorption capacity of ferrite was 14 mg/g at pH 3 and decreased with increasing pH due to enhanced electrostatic repulsion between As(V) and the adsorbent surface. Desorption of As(V) using six different acid and salt solutions showed that the desorption rate decreased in an order of H3PO4 > Na3PO4 > H2SO4 > Na2SO4 > HCl > HNO3. These results suggest that magnetic ferrite without surface modification is an effective adsorbent for removing As(V) from water, which was confirmed by the effective removal of As(V) from contaminated groundwater using this material. The used material can then be recovered using a magnet because of its paramagnetism; the adsorbed As(V) on the material can be recovered using H3PO4 or Na3PO4 solutions. 

Adsorption; Arsenate; Contaminated groundwater; Magnetic ferrite; As K-edge XANES